Whilst electronic watches are widely available, they have tended to be of relatively thick construction, that is thick in the sense measured outwardly from the wrist of a user when the watch is worn as a wrist watch. There are a number of reasons for this and one of the main reasons has been the size of the battery. Thus, whilst very small batteries are known, the smaller the battery the lower the energy stored and so there is a limit to the minimum size of a battery which can give enough energy to operate the watch correctly for reasonable lengths of time.
The problem is exacerbated when the display of the watch requires illumination for night time viewing, e.g. by means of a small micro-lamp, and/or when a sound alarm function is provided. Thus, whilst the electronic circuits themselves and a liquid crystal display have minute power requirements, a back light for the illumination of such a display and/or a sound alarm represent a considerable drain on the battery resources when they are operated.
In the quest to make electronic watches thinner, different battery designs have been adopted but it has been found that a limit has been reached where, to achieve thinness of the watch, a very thin battery is available but of a relatively large diameter. The result is that there is a conflict between the diameter of the battery and the overall size or width of the display. Making the battery of smaller diameter reduces its life and making the display of smaller size may limit the appeal of the watch since one might have a relatively large diameter casing in which is a relatively small display.
Many electronic watches are provided with some form of alarm sound output and this can be achieved by means of a small buzzer or loudspeaker. However, such items are of relatively thick construction and so again could limit the overall thickness of the watch. Alternatively if the buzzer or loudspeaker is sufficiently small the space it takes up may force one to use a smaller battery or display, neither of which is desirable.
The invention has therefore been made with these points in mind and it is an object of the invention to provide a thin electronic watch or a thin watch module to be contained within an outer watch casing.